UNIVERSITY  OF  CALIFORNIA  Agricultural  Experiment  Station 

College  of  Agriculture  e.  w.  hilgard,  director 

BERKELEY,  CALIFORNIA 


CIRCULAR  No.  3. 

(June,  1903.) 


HOG  CHOLERA, 

By  ARCHIBALD  R.  WARD, 

Veterinarian  and  Bacteriologist. 


Symptoms. — It  is  quite  impossible  to  mention  a  series  of  symptoms  to 
be  relied  upon  always  in  recognizing  the  disease.  The  name  is  mis- 
leading, in  that  the  bowels  are  not  necessarily  loose,  but  a  diarrhea  is 
most  common.  There  may  be  constipation.  Such  animals  are  spirit- 
less and  generally  do  not  stir  about.  In  advanced  cases  there  is  a 
staggering  gait.  There  is  frequently  trouble  with  the  eyes,  causing  a 
discharge,  and  there  may  be  a  reddening  of  the  skin  on  various  parts  of 
the  body.  Some  die  of  an  acute  type  of  the  disease  within  a  few  days 
after  coming  down,  while  others  will  suffer  for  weeks  from  a  chronic 
(mild)  form. 

Post-Mortem  Appearances. — The  most  constant  of  the  diseased  altera- 
tions of  the  carcass  is  the  presence  of  little  red  spots  sprinkled  over 
the  various  organs.  They  are  found  on  the  kidneys,  on  the  intestines, 
or  stomach,  heart,  diaphragm,  lungs,  or  the  lining  of  the  lung  or  intes- 
tinal cavities  and  elsewhere.  Little  glands  colored  red  by  blood  are 
found  scattered  along  the  membrane  that  attaches  the  intestines  to  the 
back.  The  spleen  is  enlarged  and  darkened  in  color.  In  cases  of  long 
standing  there  may  be  found  ulcers  on  the  inside  of  the  intestines. 
They  are  circular  in  shape,  project  slightly,  and  are  grayish-yellow  or 
black  in  color.  These  ulcers  are  most  apt  to  be  found  in  the  large  intes- 
tine. If  ulcers  are  found,  it  is  usually  safe  to  conclude  that  the  disease  is 
hog  cholera,  but  the  absence  of  them  is  not  significant.  The  lungs  are 
not  commonly  seriously  diseased,  but  may  be  solidified  in  spots. 

How  Hog  Cholera  Is  Spread. — The  disease  is  caused  by  germs  which 
are  responsible  for  its  existence  and  spread.  The  germs  are  present  in 
the  intestinal  discharge  of  the  sick,  and  consequently  the  disease  spreads 
rapidly  when  introduced  among  pigs.     Hog  cholera  can  be  prevented 


—  2  — 

by  paying  strict  attention  to  the  various  means  by  which  it  is  spread 
from  the  sick  to  the  healthy.     Chief  among  these  are : 

1.  Purchase  of  hogs  from  diseased  herds.  The  animals  may  be 
actually  suffering  from  a  mild  attack  of  cholera  or  they  may  convey 
the  germs  upon  the  filth  adhering  to  their  bodies. 

2.  Railroad  shipping-pens,  cars,  and  other  inclosures  may  harbor 
infecting  material  dropped  by  diseased  hogs  in  transit. 

3.  There  is  an  overwhelming  amount  of  evidence  showing  that  the 
disease  may  be  carried  by  streams  of  water.  A  very  fruitful  means  of 
spreading  the  disease  is  to  throw  a  dead  hog  in  a  stream  or  to  allow 
diseased  hogs  to  have  access  to  a  stream. 

4.  The  germs  may  be  carried  from  the  diseased  to  the  healthy  by  the 
filth  adhering  to  the  shoes  of  a  man,  the  feet  of  a  dog,  or  farm  utensils. 
When  hog  cholera  is  prevalent  in  a  community,  owners  of  healthy  hogs 
should  not  go  among  sick  hogs,  because  of  the  danger  of  carrying  the 
infection  home. 

5.  Buzzards  and  other  carrion  birds  and  animals  may  spread  the 
disease. 

A  few  pigs  only  are  affected  when  the  disease  first  breaks  out,  and  if 
they  are  noticed  and  prompt  action  taken  the  spread  may  be  checked. 
The  healthy  ones  should  be  removed  from  the  pens  or  field  where  the 
disease  has  appeared,  and  be  given  a  supply  of  well  water.  Animals 
kept  in  small  inclosures  are  less  apt  to  contract  the  disease  than 
those  running  on  large  areas  of  land,  as  they  are  usually  allowed  to  do 
in  California.  Wallowing-holes  of  mud  are  conducive  to  the  spread  of 
the  disease.     The  dead  should  be  burned  or  buried  in  quicklime. 

Buildings,  feeding-troughs,  and  land  contaminated  by  sick  pigs  will 
harbor  the  disease  for  many  months.  After  an  outbreak  the  disinfection 
of  buildings  and  feeding-troughs  is  necessary  before  introducing  healthy 
hogs.     The  following  is  a  good  cheap  disinfectant: 

Crude  carbolic  acid K  gallon. 

Crude  sulfuric  acid ..- K  gallon. 

"  These  two  substances  should  be  mixed  in  tubs  or  glass  vessels.  The 
sulfuric  acid  is  very  slowly  added  to  the  carbolic  acid.  During  the 
mixing  a  large  amount  of  heat  is  developed.  The  disinfecting  power  is 
heightened  if  the  amount  of  heat  is  kept  down  by  placing  the  tub  or 
demijohn  containing  the  carbolic  acid  in  cold  water,  while  the  sulfuric 
acid  is  being  added.  The  resulting  mixture  is  added  to  water  in  the 
ratio  of  1  to  20.  One  gallon  of  mixed  acid  will  thus  furnish  20  gallons 
of  a  strong  disinfecting  solution,  having  a  slightly  milky  appearance. 
The  mixture  should  be  applied  to  the  walls  and  floors  of  the  pens,  sat- 
urating them  with  it." 

Small  yards  may  be  disinfected  with  slaked  lime.  Extensive  ranges 
are  preferably  not  used  for  a  year,  although  some  authorities  place  the 


—  3  — 

period  for  the  eradication  of  infection  by  natural  climatic  agencies  at 
six  months. 

Treatment. — There  is  no  medicinal  treatment  that  can  be  relied  upon 
to  cure  every  case  of  hog  cholera.  In  numerous  cases  medicines  have 
been  administered  and  the  animals  have  recovered,  but  such  an  occur- 
rence does  not  prove  that  the  medicine  induced  the  favorable  change. 
It  is  a  matter  of  common  observation  that  the  violence  of  the  disease 
may  abate  very  abruptly  without  apparent  cause. 

Much  can  be  done  to  ward  off  the  disease  and  perhaps  to  cure  mild 
cases  by  the  use  of  the  following  medicine  recommended  by  Dr.  D.  E. 
Salmon,  Chief  of  the  Bureau  of  Animal  Industry  of  the  United  States 
Department  of  Agriculture: 

Pounds. 

Wood  charcoal 1 

Sulfur 1 

Sodium chlorid... _ _ _ _ 2 

Sodium  bicarbonate... _ 2 

Sodium  hyposulfite _ 2 

Sodium  sulfate 1 

Antimony  sulfid  (black  antimony) ._ 1 

"  These  ingredients  should  be  completely  pulverized  and  thoroughly 
mixed.  In  case  there  is  a  diarrhea  the  sulfate  of  sodium  may  be 
omitted. 

"  The  dose  of  this  mixture  is  a  large  tablespoonful  for  each  200  pounds 
weight  of  hogs  to  be  treated,  and  it  should  be  given  only  once  a  day. 
When  hogs  are  affected  with  these  diseases  they  should  not  be  fed  on 
corn  alone,  but  they  should  have  at  least  once  a  day  soft  feed,  made  by 
mixing  bran  and  middlings,  or  middlings  and  corn  meal,  or  ground  oats 
and  corn,  or  crushed  wheat  with  hot  water,  and  then  stirring  into  this 
the  proper  quantity  of  the  medicine.  Hogs  are  fond  of  this  mixture,  it 
increases  their  appetite,  and  when  they  once  taste  of  food  with  which  it 
has  been  mixed  they  will  eat  it  though  nothing  else  will  tempt  them. 

"Animals  that  are  very  sick  and  that  will  not  come  to  the  feed  should 
be  drenched  with  the  medicine  shaken  up  with  water.  Great  care 
should  be  exercised  in  drenching  hogs  or  they  will  be  suffocated.  Do 
not  turn  the  hog  on  its  back  to  drench  it,  but  pull  the  cheek  away  from 
the  teeth  so  as  to  form  a  pouch,  into  which  the  medicine  may  be  slowly 
poured.  It  will  flow  from  the  cheek  into  the  mouth,  and  when  the  hog 
finds  out  what  it  is,  it  will  stop  squealing  and  swallow.  In  our  experi- 
ments hogs  which  were  so  sick  that  they  would  eat  nothing  have  com- 
menced to  eat  very  soon  after  getting  a  dose  of  the  remedy,  and  have 
steadily  improved  until  they  appeared  perfectly  well. 

"  This  medicine  may  also  be  used  as  a  preventive  of  these  diseases, 
and  for  this  purpose  should  be  put  in  the  feed  of  the  whole  herd.  Care 
should  of  course  be  observed  to  see  that  each  animal  receives  its  proper 


—  4  — 

share.  In  cases  where  it  has  been  given  a  fair  trial,  it  has  apparently- 
cured  most  of  the  animals  which  were  sick  and  has  stopped  the  progress 
of  the  disease  in  the  herds.  It  also  appears  to  be  an  excellent  appetizer 
and  stimulant  of  the  processes  of  digestion  and  assimilation,  and  when 
given  to  unthrifty  hogs  it  increases  the  appetite,  causes  them  to  take  on 
flesh  and  assume  a  thrifty  appearance." 

The  administration  of  the  medicine  is  useless  unless  the  patients  are 
kept  under  comfortable  conditions  with  careful  feeding. 

There  has  been  much  careful  experimental  work  done  in  an  effort  to 
produce  a  serum  for  injecting  under  the  skin  of  hogs,  to  cure  the 
cholera  or  to  immunize  the  system  against  it.  Some  experiments  have 
yielded  satisfactory  results  on  a  small  scale,  but  this  line  of  treatment 
has  not  progressed  far  enough  to  be  of  practical  use  as  yet. 

Quarantine  Regulations  for  Hog  Cholera. — Prevention  of  the  disease 
by  strict  quarantine  must  ever  be  relied  upon  to  check  the  enormous 
losses  from  hog  cholera.  Individuals  who  have  carefully  studied  the 
disease  can  accomplish  much  by  voluntarily  observing  the  precautions 
necessary  to  prevent  its  spread.  But  to  effectually  restrict  hog  cholera, 
regulations  with  the  force  of  law  must  exist,  as  well  as  a  corps  of  men  to 
enforce  them.  California  is  sadly  lacking  in  these  requisites,  and  until 
they  are  supplied  the  swine  industry  must  continue  to  suffer  appalling 
losses  annually. 

As  an  example  of  the  kind  of  measures  necessary  for  the  control  of 
hog  cholera  there  is  appended  a  copy  of  a  circular  giving  directions  for 
quarantining  infected  animals: 

MINNESOTA   STATE   BOARD  OF   HEALTH. 

CIRCULAR    OF    INFORMATION    FOR    LOCAL    HEALTH    OFFICERS. 
For  Quarantining  Hogs  Suffering  from  any  Infectious  Disease. 

The  proper  quarantine  of  hOgs  imposes  no  hardship  upon  either  the  owner  or  the 
hogs  themselves.  The  chief  purpose  of  the  Board  of  Health  in  quarantining  any  suspi- 
cious disease  among  hogs  is  to  protect  the  financial  interests  of  the  hog-raisers.  Valua- 
ble time  is  often  lost  before  quarantine  is  established.  This  permits  serious  spread  of 
the  disease  to  take  place,  and  makes  its  control  much  more  difficult. 

The  disease  now  prevailing  in  different  portions  of  the  State  varies  in  symptoms  in 
different  localities  and  in  different  herds.  It  may  be  set  down  as  a  rule,  however,  when 
any  infectious  (catching)  disease  appears  among  swine  that  it  is  hog  cholera,  modified 
more  or  less  in  symptoms  by  well-known  complications. 

When  hogs  begin  to  sicken  and  die  during  the  prevalence  of  hog  cholera  the  disease 
should  be  reported  to  the  local  health  officer  or  chairman  of  the  town  board,  and  quar- 
antine should  be  established  at  once.  It  is  a  simple  matter  to  release  quarantine,  and 
should  it  be  proven  that  the  disease  is  not  hog  cholera,  no  harm  has  been  done  by  such 
quarantine. 

All  health  officers  and  acting  health  officers  are  therefore  instructed  to  see  that  sus- 
picious outbreaks  of  disease  among  hogs  are  properly  quarantined. 

The  health  officer  should  explain  to  the  owner  or  keeper  the  nature  and  conditions 
of  quarantine,  and  see  that  the  conditions  are  rigidly  enforced  until  quarantine  is 
released. 


—  5  — 

Hog  cholera  is  often  spread  by  water  in  small  streams  and  lakes,  and  for  this  reason 
hogs  must  not  be  buried  near  any  such  lake  or  watercourse. 

Poultry  should  not  be  allowed  access  to  yards  or  pens  where  hogs  are  confined  during 
the  hog  cholera  season,  and  pigeons  and  crows  should  be  shot  or  otherwise  frightened 
away,  because  of  danger  that  they  may  spread  the  disease. 

The  health  officer  or  inspector  should  always  wear  overalls  and  overshoes  or  rubbers 
when  going  among  diseased  hogs.  These  overalls  and  overshoes  or  rubbers  should 
always  be  kept  a  safe  distance  from  healthy  hogs  and  from  other  agents  which  might 
convey  the  disease. 

Quarantine  cards  must  not  be  removed  until  six  months  after  the  last  hog  has  died 
or  recovered,  and  the  premises  disinfected  in  a  way  satisfactory  to  the  local  board  of 
health. 

Farmers  should  be  urged  to  dispose  of  marketable  hogs  for  slaughter  as  soon  as  sus- 
pected hog  cholera  appears  in  the  neighborhood. 

Racks  and  wagon  boxes  used  for  hauling  such  hogs  must  be  tight  and  so  constructed 
at  the  bottom  as  to  prevent  the  scattering  of  manure  and  litter  along  the  highway. 

Racks  and  wagon  boxes,  which  have  been  used  for  transporting  such  hogs,  must  be 
thoroughly  disinfected  as  soon  as  the  work  is  finished.  All  parts  of  the  wagon  that 
have  come  in  contact  with  the  hogs  or  litter  must  be  thoroughly  disinfected.  Five  per 
cent  solution  of  crude  carbolic  acid  in  water  is  cheap  and  effective. 

Neighbors  on  whose  farms  the  disease  has  not  yet  appeared  should  never  be  allowed 
to  help  haul  the  hogs  from  infected  farms,  as  there  is  great  danger  that  the  disease  will 
be  spread  from  farm  to  farm  by  such  action. 

The  following  placards  are  required  to  be  posted  in  a  conspicuous 
place  by  owners  of  swine  in  a  community  where  the  disease  exists: 

MINNESOTA   STATE   BOARD   OF   HEALTH. 

HOG    CHOLERA! 
Exists  on  These  Premises. 

All  persons,  excepting  the  owner,  duly  authorized  attendants,  or  medical  advisers,  are 
forbidden  to  enter  any  inclosures  where  hogs  are  kept  on  these  premises,  until  this  card 
has  been  removed  by  permission  from  the  State  or  local  Board  of  Health. 

Hogs  must  not  be  removed  from  these  premises  after  date  of  this  card,  until  six 
months  after  the  last  case  of  suspicious  swine  disease  has  died  or  recovered,  except  in 
the  following  cases:  1st,  by  permission  in  writing  given  by  the  State  Board  of  Health ; 
and  2d,  dressed  carcasses  of  healthy  hogs  killed  under  inspection  of  the  State  or  local 
Board  of  Health. 

No  hogs,  excepting  those  hereby  quarantined  and  their  offspring,  shall  be  allowed 
upon  these  premises  until  six  months  after  the  last  hog  has  died  or  recovered.  During 
this  period  of  six  months  no  other  domestic  animal  shall  be  permitted  in  these  pens  for 
any  reason  whatever. 

Parties  living  on  this  place  must  not  go  near  pens  or  yards  where  hogs  are  kept  on 
other  farms. 

Keepers  of  these  hogs  will  be  held  responsible  for  the  unauthorized  removal  of  this 
notice,  and  for  allowing  any  swine  hereby  quarantined  to  escape  from  these  pens  or 
yards  and  run  at  large. 

Bv  order  of 

,  Health  Officer. 

Dated ,  19—. 

Chapter  233,  Laws  of  1897  (Minnesota).— Section  9.  Any  person  violating  any  pro- 
vision of  this  Act  or  any  rule  or  regulation  made  by  the  State  Board  of  Health,  or  by 
any  local  Board  of  Health,  or  any  order  made  by  any  such  board  under  the  authority 
hereof,  shall  be  guilty  of  a  misdemeanor  and  be  punished  by  a  fine  of  not  less  than 
twenty-five  (25)  or  more  than  one  hundred  (100)  dollars,  or  by  imprisonment  for  not  less 
than  thirty  (30)  or  more  than  ninety  (90)  days. 


—  6  — 

[For  Use  by  Owners  of  Hogs.] 

NOTICE. 

All  unauthorized  persons  are  forbidden,  under  penalty  of  the  law,  to  approach  on 
these  premises  nearer  than  50  feet  to  any  pens  or  yards  where  hogs  are  confined. 


Signature  of  owner. 

Chapter  233,  Laws  of  1897  (Minnesota).— Section  11.  Whenever  during  the  preva- 
lence in  the  State  of  any  contagious  or  infectious  disease  among  domestic  animals,  the 
owner  shall  post  on  his  premises  a  notice  forbidding  all  persons  not  authorized  by  State 
or  local  Boards  of  Health  to  enter  any  building  or  inclosure  on  said  premises,  without 
permission  from  said  owner,  it  shall  be  a  misdemeanor  to  enter  upon  such  premises, 
punishable  by  a  fine  of  not  less  than  twenty-five  dollars  ($25)  nor  more  than  one  hun- 
dred dollars  ($100),  or  by  imprisonment  for  not  less  than  thirty  (30)  days  nor  more  than 
ninety  (90)  days. 

Swine  Plague. — This  disease  is  as  common  as  hog  cholera,  and  most 
outbreaks  of  the  cholera  are  complicated  by  it.  The  symptoms  do  not 
greatly  differ  from  those  of  hog  cholera,  except  that  it  is  more  commonly 
a  disease  of  the  lungs,  and  consequently  there  is  apt  to  be  coughing. 
The  treatment  and  methods  of  sanitation  do  not  differ  markedly  from 
those  laid  down  for  hog  cholera.  In  consequence,  the  definite  recogni- 
tion of  the  disease  is  not  of  great  practical  importance  to  the  owner  of 
the  animal. 

Soap  Powder  Poisonous  to  Hogs. — Some  deaths  among  hogs  in  New 
York  State  were  found  by  Dr.  V.  A.  Moore,  of  the  New  York  State  Vet- 
erinary College,  to  be  caused  by  one  of  the  soap  powders  in  common 
use.  Upon  investigation  it  was  found  that  the  soap  powder  was  used  in 
washing  dishes  in  a  kitchen,  and  that  the  dishwater  found  its  way  to  the 
hogs  in  swill.  Carefully  conducted  experiments  later  showed  that  pigs 
could  be  killed  by  feeding  them  amounts  of  soap  powder  smaller  than 
commonly  used  in  kitchens.  In  cases  of  deaths  among  swine  it  is, 
therefore,  desirable  to  ascertain  that  the  food  is  wholesome. 


SACRAMENTO  : 
SHANNON.        -       -      SUPT.    STATE    PRINTING. 
1903. 


Digitized  by  the  Internet  Archive 

in  2012  with  funding  from 

University  of  California,  Davis  Libraries 


http://www.archive.org/details/hogcholera03ward 


